Why do I have giant red letters that say DEMO on the screen of my Tagital Tablet 9inch?

I recently purchased a Tagital Tablet 9inch for my autistic daughter last month. After a week of having it and using it, working perfectly fine, bright red letters appeared on the screen that say DEMO. I've tried a completely factory reset, which removed everything she downloaded, which sent her into a tantrum and meltdown, and it still didn't work. Went into the settings, found in the display there were DEMO options, yet you cannot select these at all. Tried hard reset. NOTHING WORKS. I am getting so unbelievably irritated. There has got to be someone out there that has had the same damn problem. HELP!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!

Sorry to hear of your problems have you contacted their customer service call them up and demand don't hold back only then will you get what you deserve; the answers! Sometimes tech does this but its not your fault. Maybe visit the shop and complain and ask for a replacement should push come to shove.